The invention relates in general to a cylinder lock, and in particular to a lock having a core provided with a keyway adapted for receiving a key having on one side thereof recesses or projections for controlling arresting tumblers of the lock and also having longitudinal ribs or grooves formed on another side thereof to cooperate with complementary guiding grooves or ribs in the keyway.
Locks of the above-described kind are known and particularly in the form of cylinder locks having two or more segmented tumbler pins are in wide use. Locks are also known in which single-piece tumbler pins are brought by the inserted key into the arresting or releasing position. Nevertheless, all these known locks have various disadvantages as regards the limitations of their number of variations, the safety against scanning and the safety against forcible opening.